1. Field of the Invention
The present invention relates to a front body structure for use in a vehicle, and more particularly, to a front body structure for use in a vehicle having an acceleration sensor.
2. Background Information
It is known that Japanese Utility Model Application Laid-Open No. 2-6055 discloses one example of a conventional front body structure for use in a vehicle which includes an acceleration sensor.
FIG. 13 illustrates a front body structure, in which a front frame is provided at a front end portion of a vehicle body 110 in a transverse direction thereof, with a plurality of acceleration sensors 112 being disposed on the front frame. When sudden acceleration is imparted to the vehicle body 110, the acceleration sensors 112 activate an air bag device which is provided in an occupant's room.
As shown in FIG. 14, in the above-identified front body structure, one mounting member 116, which is disposed in the forward direction of the vehicle body 110, acquires higher rigidity than the other mounting member 118 that is disposed in the rearward direction thereof, these mounting members being used to fix the acceleration sensors 112 to a front frame 114. This structure thus prevents the acceleration sensors 112 from retarding.
However, in such a front body structure, accelerations which act on the acceleration sensors 112 may vary depending on the rigidity of the vehicle body 110 and the like. The acceleration sensors 112 operate over a wide range of accelerations imparted to the vehicle body 110. Accordingly, it is extremely difficult from a technical viewpoint to ensure that the acceleration sensors 112 operate at a speed that is approximate to the predetermined acceleration value.
Another type of front body structure is recently known, in which a crush body is disposed in front of a front-side member so as to absorb a load imparted from the front of a vehicle body when the load is lower than a predetermined value, thereby eliminating deformation of the front-side member. (For this structure, reference is made, for example, to Japanese Patent Application Laid-Open No. 2-175452.) Accordingly, it is preferable in this case that the acceleration sensors 112 operate while the crush box is in the process of deformation, thereby activating the air bag device.